When a bored copy-shop employee spotted a chilling letter on the copy machine, he was left with an ethical dilemma. On The Gist, Emily Yoffe of Slate’sDear Prudence column explains when it’s your duty to report discussions of sexual conduct with minors. Plus, Slate columnistReihan Salam reveals how Rand Paul and Chris Christie are courting black voters. For the Spiel, Mike responds to flack for defending race-car driver Tony Stewart on last night’s All In With Chris Hayes.